A Couple Of New DOS PCs Appear

November 23, 2025 by No comments

An interesting trend over the last year or two has been the emergence of modern retrocomputer PCs, recreations of classic PC hardware from back in the day taking advantage of modern parts alongside the venerable processors. These machines are usually very well specified for a PC from the 1980s, and represent a credible way to run your DOS or early Windows software on something close to the original. [CNX Software] has news of a couple of new ones from the same manufacturer in China, one sporting a 386sx and the other claiming it can take either an 8088 or an 8086.

Both machines use the same see-through plastic case, screen, and keyboard, and there are plenty of pictures to examine the motherboard. There are even downloadable design files, which is an interesting development. They come with a removable though proprietary looking VGA card bearing a Tseng Labs ET4000, a CF card interface, a USB port which claims to support disk drives, a sound card, the usual array of ports, and an ISA expansion for which a dock is sold separately. The battery appears to be a LiPo pouch cell of some kind.

If you would like one they can be found through the usual channels for a not-outrageous price compared to similar machines. We can see the attraction, though maybe we’ll stick with an emulator for now. If you’d like to check out alternatives we’ve reported in the past on similar 8088 and 386sx computers.

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Hackaday Links: November 23, 2025

November 23, 2025 by 3 Comments

Remember the Key Bridge collapse? With as eventful a year as 2025 has been, we wouldn’t blame anyone for forgetting that in March of 2024, container ship MV Dali plowed into the bridge across Baltimore Harbor, turning it into 18,000 tons of scrap metal in about four seconds, while taking the lives of six very unlucky Maryland transportation workers in the process. Now, more than a year and a half after the disaster, we finally have an idea of what caused the accident. According to the National Transportation Safety Board’s report, a loss of electrical power at just the wrong moment resulted in a cascade of failures, leaving the huge vessel without steerage. However, it was the root cause of the power outage that really got us: a wire with an incorrectly applied label.

Continue reading “Hackaday Links: November 23, 2025” →

Retrotechtacular: Computers In Schools? 1979 Says Yes

November 23, 2025 by 13 Comments

The BBC wanted to show everyone how a computer might be used in schools. A program aired in 1979 asks, “Will Computers Revolutionise Education?” There’s vintage hardware and an appearance of PILOT, made for computer instructions.

Using PILOT looks suspiciously like working with a modern chatbot without as much AI noise. The French teacher in the video likes that schoolboys were practicing their French verb conjugation on the computer instead of playing football.

If you want a better look at hardware, around the five-minute mark, you see schoolkids making printed circuit boards, and some truly vintage oscilloscope close-ups. There are plenty of tiny monitors and large, noisy printing terminals.

You have to wonder where the eight-year-olds who learned about computers in the video are today, and what kind of computer they have. They learned binary and the Towers of Hanoi. Their teacher said the kids now knew more about computers than their parents did.

As a future prediction, [James Bellini] did pretty well. Like many forecasters, he almost didn’t go far enough, as we look back almost 50 years. Sure, Prestel didn’t work out as well as they thought, dying in 1994. But he shouldn’t feel bad. Predicting the future is tough. Unless, of course,  you are [Arthur C. Clarke].

Continue reading “Retrotechtacular: Computers In Schools? 1979 Says Yes” →

A 3D-printed assembly standing on short legs is visible. A portion extends upward with the word "Nord" sunk into it. Cables extend from one side of the upright portion, and a side view of a circuit board is visible at the front of the assembly.

Measuring Earth’s Rotation With Two Gyroscopes

November 23, 2025 by 21 Comments

We’ve probably all had a few conversations with people who hold eccentric scientific ideas, and most of the time they yield nothing more than frustration and perhaps a headache. In [Bertrand Selva]’s case, however, a conversation with a flat-earth believer yielded a device that uses a pair of gyroscopes to detect earth’s rotation, demonstrating that rotation exists without the bulkiness of a Foucalt pendulum.

[Bertrand] built his apparatus around a pair of BMI160 MEMS gyroscopes, which have a least significant bit for angular velocity corresponding to 0.0038 degrees per second, while the earth rotates at 0.00416 degrees per second. To extract such a small signal from all the noise in the measurements, the device makes measurements with the sensors in four different positions to detect and eliminate the bias of the sensors and the influence of the gravitational field. Before running a test, [Bertrand] oriented the sensors toward true north, then had a stepper motor cycle the sensors through the four positions, while a Raspberry Pi Pico records 128 measurements at each position. It might run the cycle as many as 200 times, with error tending to decrease as the number of cycles increases.

A Kalman filter processes the raw data and extracts the signal, which came within two percent of the true rotational velocity. [Bertrand] found that the accuracy was strongly dependent on how well the system was aligned to true north. Indeed, the alignment effect was so strong that he could use it as a compass.

In the end, the system didn’t convince [Bertrand]’s neighbor, but it’s an impressive demonstration nonetheless. This system is a bit simpler, but it’s also possible to measure the earth’s rotation using a PlayStation. For higher precision, check out how the standards organizations manage these measurements.

Styrofoam watercraft, PCB hydrofoil

A PCB Can Be A Hydrofoil, If It Really Wants To

November 23, 2025 by 7 Comments

You know those old cliche that the younger generations have begun to cynically despise: “follow your dreams!” “You can be anything you put your mind to!” — well, perhaps they are true on occasion. For instance when [rctestflight] had PCBs that dreamed of becoming a hydrofoil, he found a way to make that dream come true.

It’s kind of obvious in retrospect: printed circuit boards are made of FR4, which is a form of fiberglass, and you know what else is commonly made of fiberglass? Boats. So yes, the material is suited for this task. The fact that solder joints hold up to use in a little remote-control hydrofoil is less obvious, but good to know. It certainly makes for easier assembly for those of us who have developed an allergy to epoxy.

Ease of assembly wasn’t really the point here: the point was that by making the “mast” of the hydrofoil out of PCB– that’s the part that holds the underwater wing– [rctestflight] figured he could (shock!) print a circuit onto it. Specifically, a liquid-level sensor, and because microcontrollers are so cheap these days he went the “total overkill” route of embedding an ESP32 on each mast. He started with a resistive sensor, but since those self-corrode too quickly, the team switched to a capacitive sensor that doesn’t need to form a galvanic cell in salt water. Come to think of it, that might still be a problem with the solder joint between the PCBs. Good thing nobody will be riding this one.

Having such a sensor and brain close-coupled allows for a faster control loop than the sonar [rctestflight] had previously been using to control his hydrofoil’s altitude.. Pivoting each mast with its own servo made for a smooth flight over the water— well, once they got the PID tuning set, anyway. Check it out in the video embedded below.

We’ve seen PCB used for enclosures before, and even the chassis of a rover, but using it for a hydrofoil is a new hack. Continue reading “A PCB Can Be A Hydrofoil, If It Really Wants To” →

Deep Fission Wants To Put Nuclear Reactors Deep Underground

November 23, 2025 by 43 Comments

Today’s pressurized water reactors (PWRs) are marvels of nuclear fission technology that enable gigawatt-scale power stations in a very compact space. Though they are extremely safe, with only the TMI-2 accident releasing a negligible amount of radioactive isotopes into the environment per the NRC, the company Deep Fission reckons that they can make PWRs even safer by stuffing them into a 1 mile (1.6 km) deep borehole.

Their proposed DB-PWR design is currently in pre-application review at the NRC where their whitepaper and 2025-era regulatory engagement plan can be found as well. It appears that this year they renamed the reactor to Deep Fission Borehole Reactor 1 (DFBR-1). In each 30″ (76.2 cm) borehole a single 45 MWt DFBR-1 microreactor will be installed, with most of the primary loop contained within the reactor module.

As for the rationale for all of this, at the suggested depth the pressure would be equivalent to that inside the PWR, with in addition a column of water between it and the surface, which is claimed to provide a lot of safety and also negates the need for a concrete containment structure and similar PWR safety features. Of course, with the steam generator located at the bottom of the borehole, said steam has to be brought up all the way to the surface to generate a projected 15 MWe via the steam turbine, and there are also sampling tubes travelling all the way down to the primary loop in addition to ropes to haul the thing back up for replacing the standard LEU PWR fuel rods.

Whether this level of outside-the-box-thinking is a genius or absolutely daft idea remains to be seen, with it so far making inroads in the DoE’s advanced reactor program. The company targets having its first reactor online by 2026. Among its competition are projects like TerraPower’s Natrium which are already under construction and offer much more power per reactor, along with Natrium in particular also providing built-in grid-level storage.

One thing is definitely for certain, and that is that the commercial power sector in the US has stopped being mind-numbingly boring.

 

Saving A Rental Ebike From The Landfill

November 23, 2025 by 13 Comments

One of the hardest things about owning a classic car is finding replacement parts. Especially if the car is particularly old or rare, or if the parent company is now out of business, sometimes this can be literally impossible and a new part will have to be manufactured from scratch. The same is true of bicycles as well, and there are plenty of defunct bicycle manufacturers to choose from. [Berm Peak] found a couple old rental ebikes from a company that’s not in business anymore and set about trying to get them working again. (Video, embedded below.)

Of course, unlike many classic cars, ebikes are encumbered by proprietary electronics and software that are much harder to replace than most physical components. As a result, these bikes get most of their electronics pulled out and directly replaced. This bike also had a seized motor, so [Berm Peak] replaced it with another hub motor he had in his shop. Some of the other highlights in the build include a custom 3D-printed latching mechanism for the battery’s attachment point at the frame, a 3D printed bezel for the new display and control unit, and the reuse of some of the other fun parts of the bike like the front basket and integrated headlight.

There are a few reasons for putting so much work into a bike like this. For this specific bike at least, the underlying components are worth saving; the sturdy metal frame and belt drivetrain are robust and won’t need much maintenance in the long term. It also only cost around $500 in parts to build a bike that would take around $2,000 to purchase new, so there’s some economic incentive as well. And in general it’s more fun and better for the world to fix things like this up and get them running again rather than buying something new off the shelf. And while proprietary electronics like those found on this bike are ubiquitous in the ebike world, they’re not all completely closed-source.

Continue reading “Saving A Rental Ebike From The Landfill” →